Research efforts this year have been directed at shortening the lengthy procedure for preparation of hybrid antibody in order to make more material available for ensuing studies. Two major modifications have been introduced; a) the substitution of sodium sulfate for ammoniumsulfate for use in salt precipitation of both human and sheep immunoglobulin G(IgG) and b) the replacement of Beta-mercaptoethylamine with sodium borohydride in the reduction step of the F(ab1)2 fragments from sheep anti IgG and sheep antiferritin along with elimination of use of the AG 50 x 2 ion exchange column. This modified method has been successfully employed to localize viral antigens (in the electron microscope) on the surface of herpes infected KB cells.